Zoological medicine and public health

Public-health issues regarding zoological collections and free-ranging wildlife have historically been linked to the risk of transmission of zoonotic diseases and accidents relating to bites or injection of venom or toxins by venomous animals. It is only recently that major consideration has been given worldwide to the role of the veterinary profession in contributing to investigating zoonotic diseases in free-ranging wildlife and integrating the concept of public health into the management activities of game preserves and wildlife parks. At the veterinary undergraduate level, courses in basic epidemiology, which should include outbreak investigation and disease surveillance, but also in population medicine, in infectious and parasitic diseases (especially new and emerging or re-emerging zoonoses), and in ecology should be part of the core curriculum. Foreign diseases, especially dealing with zoonotic diseases that are major threats because of possible agro-terrorism or spread of zoonoses, need to be taught in veterinary college curricula. Furthermore, knowledge of the principles of ecology and ecosystems should be acquired either during pre-veterinary studies or, at least, at the beginning of the veterinary curriculum. At the post-graduate level, master's degrees in preventive veterinary medicine, ecology and environmental health, or public health with an emphasis on infectious diseases should be offered to veterinarians seeking job opportunities in public health and wildlife management.     

Control of infectious diseases of wildlife in Europe

During the last 30 years, new epidemiological patterns have emerged as free-ranging wildlife have become progressively more involved in the epidemiology of both common and emerging infectious diseases of humans and domestic animals. This has been seen in rabies, bovine tuberculosis and more recently in wild-boar classical swine fever. Emerging diseases are of interest to veterinarians as well as public health officials but attempts to control these diseases have not always been successful as in wildlife populations control of either host or pathogen can present particular problems. Lessons should be learnt from previous experiences to help in the management of new emerging diseases in the future.     

Development of the England Wildlife Health Strategy--a framework for decision makers

Diseases in wildlife have been recognised as having the potential to affect human health, livestock health and species conservation. In order to assess and respond to these potential risks in an effective and a proportionate way, the UK Government initiated development of the Wildlife Health Strategy to provide a framework for decision making. The England Wildlife Health Strategy (EWHS) has been developed through extensive consultation. Discussions and negotiations with government departments, agencies, non-governmental public bodies and wildlife organisations were held to obtain advice and input on specific and specialised aspects of wildlife health. A series of workshops to investigate the application of innovative science to wildlife health policy contributed further. A formal public consultation was held that proposed a range of actions to implement the strategy. A summary of responses to this consultation was published in October 2007. The EWHS was published in June 2009 and provides a framework for a generic four-stage approach to wildlife health that can be adopted by decision makers both within and outside government.     

Zoonotic aspects of Mycobacterium bovis and Mycobacterium avium-intracellulare complex (MAC)

Pathogens that are transmitted between the environment, wildlife, livestock and humans represent major challenges for the protection of human and domestic animal health, the economic sustainability of agriculture, and the conservation of wildlife. Among such pathogens, the genus Mycobacterium is well represented by M. bovis, the etiological agent of bovine tuberculosis, M. avium ssp. paratuberculosis (Map) the etiological agent of Johne disease, M. avium ssp. avium (Maa) and in a few common cases by other emergent environmental mycobacteria. Epidemiologic surveys performed in Europe, North America and New Zealand have demonstrated the existence and importance of environmental and wildlife reservoirs of mycobacterial infections that limit the attempts of disease control programmes. The aim of this review is to examine the zoonotic aspects of mycobacteria transmitted from the environment and wildlife. This work is focused on the species of two main groups of mycobacteria classified as important pathogens for humans and animals: first, M. bovis, the causative agent of bovine tuberculosis, which belongs to the M. tuberculosis complex and has a broad host range including wildlife, captive wildlife, domestic livestock, non-human primates and humans; the second group examined, is the M. avium-intracellulare complex (MAC) which includes M. avium ssp. avium causing major health problems in AIDS patients and M. avium ssp. paratuberculosis the etiological agent of Johne disease in cattle and identified in patients with Crohn disease. MAC agents, in addition to a broad host range, are environmental mycobacteria found in numerous biotopes including the soil, water, aerosols, protozoa, deep litter and fresh tropical vegetation. This review examines the possible reservoirs of these pathogens in the environment and in wildlife, their role as sources of infection in humans and animals and their health impact on humans. The possibilities of control and management programmes for these mycobacterial infections are examined with regards to the importance of their natural reservoirs.     

The transmissible spongiform encephalopathies: disease risks for North America.

Transmissible spongiform encephalopathies exotic to North America (BSE and associated diseases) are unlikely to be introduced or to persist should they be introduced into the United States [2]. Domestic TSEs (scrapie, CWD, and TME) seem to be relatively restricted in their host range, and none of these diseases is known to naturally cause disease in cattle. It is important that surveillance for TSEs continues, however, particularly in cattle because of the extreme consequences to the livestock industries, and potentially, public health, if BSE becomes established. Because the TSEs have implications beyond effects on their natural host species, adequate surveillance, control, and even eradication of these diseases should be goals for the livestock industries, wildlife managers, and animal health agencies in the United States.     

The role of wildlife in transboundary animal diseases

This paper identifies some of the more important diseases at the wildlife-livestock interface and the role wildlife plays in disease transmission. Domestic livestock, wildlife and humans share many similar pathogens. Pathogens of wild or domestic animal origin that can cause infections in humans are known as zoonotic organisms and the converse are termed as anthroponotic organisms. Seventy-seven percent of livestock pathogens and 91% of domestic carnivore pathogens are known to infect multiple hosts, including wildlife. Understanding this group of pathogens is critical to public health safety, because they infect a wide range of hosts and are most likely to emerge as novel causes of infection in humans and domestic animals. Diseases at the wildlife-livestock interface, particularly those that are zoonotic, must be an area of focus for public health programs and surveillance for emerging infectious diseases. Additionally, understanding wildlife and their role is a vital part of understanding the epidemiology and ecology of diseases. To do this, a multi-faceted approach combining capacity building and training, wildlife disease surveillance, wildlife-livestock interface and disease ecology studies, data and information sharing and outbreak investigation are needed.     

Leptospira interrogans at the Human–Wildlife Interface in Northern Botswana: A Newly Identified Public Health Threat

Leptospirosis is the most widespread zoonosis in the world. In northern Botswana, humans live in close proximity to a diversity of wildlife and peridomestic rodents and may be exposed to a variety of zoonotic pathogens. Little is known regarding the occurrence and epidemiology of L. interrogans in Africa despite the recognized global importance of this zoonotic disease and the threat it poses to public health. In Botswana, banded mongooses (Mungos mungo) live in close proximity to humans across protected and unprotected landscapes and may be a useful sentinel species for assessing the occurrence of zoonotic organisms, such as L. interrogans. We utilized PCR to screen banded mongoose kidneys for leptospiral DNA and identified 41.5% prevalence of renal carriage of L. interrogans (exact binomial 95% CI 27.7–56.7%, n = 41). Renal carriage was also detected in one Selous' mongoose (Paracynictis selousi). This is the first published confirmation of carriage of L. interrogans in either species. This is also the first report of L. interrogans occurrence in northern Botswana and the only report of this organism in a wildlife host in the country. Pathogenic Leptospira are usually transmitted indirectly to humans through soil or water contaminated with infected urine. Other avenues, such as direct contact between humans and wildlife, as well as consumption of mongooses and other wildlife as bushmeat, may pose additional exposure risk and must be considered in public health management of this newly identified zoonotic disease threat. There is a critical need to characterize host species involvement and pathogen transmission dynamics, including human–wildlife interactions that may increase human exposure potential and infection risk. We recommend that public health strategy be modified to include sensitization of medical practitioners to the presence of L. interrogans in the region, the potential for human infection, and implementation of clinical screening. This study illustrates the need for increased focus on neglected zoonotic diseases as they present an important threat to public health.     

动物园兽医的使命及发展思路

野生动物的移地保护和保护教育是现代动物园的主要功能,兽医在保障野生动物健康方面承担着重要的使命。动物园兽医在本质上是医学的一个特殊分枝,由于野生动物及其疾病种类的复杂性和个人精力、能力的局限性,动物园兽医的职业化和专业化是提高野生动物健康保障能力的根本出路;应激因素对圈养动物的健康造成很大的威胁,而适度驯化则可以最大限度地减少应激的发生;在国内建立区域动物园兽医服务网络、建立兽医行业内部信息交流平台是提高动物园兽医行业整体水平的基本思路：正确的疾病诊断和规范的处方,以及全面关注动物的基本需求、积极主动的疾病防疫等在兽医日常工作中占有同等重要的地位。由于兽医掌握了动物发病和死亡的第一手资料,动物园应当为兽医参与动物管理提供条件。     

Opportunities and obstacles to collecting wildlife disease data for public health purposes: results of a pilot study on Vancouver Island, British Columbia

Existing sources of wildlife morbidity and mortality data were evaluated and 3 pilot active surveillance projects were undertaken to compare and contrast methods for collecting wildlife disease data on Vancouver Island for public health purposes. Few organizations could collect samples for diagnostic evaluation, fewer still maintained records, and none regularly characterized or reported wildlife disease for public health purposes. Wildlife rehabilitation centers encountered the greatest variety of wildlife from the largest geographic area and frequently received submissions from other organizations. Obstacles to participation included the following: permit restrictions; financial disincentives; staff safety; no mandate to collect relevant data; and lack of contact between wildlife and public health agencies. Despite these obstacles, modest investments in personnel allowed novel pathogens of public health concern to be tracked. Targeted surveillance for known pathogens in specific host species, rather than general surveys for unspecified pathogens, was judged to be a more effective and efficient way to provide useful public health data.     

野生动物口服疫苗的研究概况

野生动物是大量病原体的天然宿主,野生动物疫源疫病严重威胁人类健康。本文对近年来国外野生动物口服疫苗的研究概况进行综述,以期为我国野生动物保护及野生动物疫源疫病的防治提供资料。     

Emerging and exotic zoonotic disease preparedness and response in the United States - coordination of the animal health component

For the response to a zoonotic disease outbreak to be effective, animal health authorities and disease specialists must be involved. Animal health measures are commonly directed at known diseases that threaten the health of animals and impact owners. The measures have long been applied to zoonotic diseases, including tuberculosis and brucellosis, and can be applied to emerging diseases. One Health (veterinary, public, wildlife and environmental health) and all-hazards preparedness work have done much to aid interdisciplinary understanding and planning for zoonotic diseases, although further improvements are needed. Actions along the prevention, preparedness, response and recovery continuum should be considered. Prevention of outbreaks consists largely of import controls on animals and animal products and biosecurity. Preparedness includes situational awareness, research, tool acquisition, modelling, training and exercises, animal movement traceability and policy development. Response would include detection systems and specialized personnel, institutions, authorities, strategies, methods and tools, including movement control, depopulation and vaccination if available and appropriate. The specialized elements would be applied within a general (nationally standardized) system of response. Recovery steps begin with continuity of business measures during the response and are intended to restore pre-event conditions. The surveillance for novel influenza A viruses in swine and humans and the preparedness for and response to the recent influenza pandemic illustrate the cooperation possible between the animal and public health communities.     

Marine Mammal Zoonoses: A Review of Disease Manifestations

Marine mammals evoke strong public affection as well as considerable scientific interest. However, the resultant close contact with marine wildlife poses human health risks, including traumatic injury and zoonotic disease transmission. The majority of zoonotic marine mammal diseases result in localized skin infections in man that resolve spontaneously or with appropriate medical therapy. However, other marine mammal zoonoses, if left untreated, induce life‐threatening systemic diseases that could pose public health risks. As the number of zoonotic diseases rises, the diagnosis of and treatment for these emerging pathogens pose special challenges requiring the expertise of physicians, veterinarians and wildlife biologists. Here, we provide a comprehensive review of the bacterial, viral and fungal marine mammal zoonotic diseases that we hope will be utilized by public health professionals, physicians, veterinarians and wildlife biologists to better understand, diagnose and prevent marine mammal zoonotic diseases.     

The future of veterinary parasitology: a time for change?

The future of veterinary parasitology is discussed at a time when R&D funding from the pharmaceutical industry is declining, yet the opportunities for veterinary parasitologists to diversify their activities has never been greater. Emerging and re-emerging areas requiring input from veterinary parasitologists include: veterinary public health; conservation and wildlife diseases; emerging and exotic infectious diseases; surveillance strategies; economic effects of parasitic diseases; aquaculture; molecular epidemiology; dietary and biological control of parasitic diseases; animal welfare; organic agricultural systems; novel vaccination strategies; drug target characterisation and rational drug design. Without change, the survival of veterinary parasitology as a viable, distinct discipline is under threat. In this environment, veterinary parasitologists must be adaptable, imaginative and pro-active in terms of setting the agendas for establishing strategic alliances, promoting research needs and developing research programs.     

Population genetics of Toxoplasma gondii: new perspectives from parasite genotypes in wildlife

Toxoplasma gondii, a zoonotic protozoal parasite, is well-known for its global distribution and its ability to infect virtually all warm-blooded vertebrates. Nonetheless, attempts to describe the population structure of T. gondii have been primarily limited to samples isolated from humans and domesticated animals. More recent studies, however, have made efforts to characterize T. gondii isolates from a wider range of host species and geographic locales. These findings have dramatically changed our perception of the extent of genetic diversity in T. gondii and the relative roles of sexual recombination and clonal propagation in the parasite's lifecycle. In particular, identification of novel, disease-causing T. gondii strains in wildlife has raised concerns from both a conservation and public health perspective as to whether distinct domestic and sylvatic parasite gene pools exist. If so, overlap of these cycles may represent regions of high probability of disease emergence. Here, we attempt to answer these key questions by reviewing recent studies of T. gondii infections in wildlife, highlighting those which have advanced our understanding of the genetic diversity and population biology of this important zoonotic pathogen.     

由媒体对野生动物狩猎权拍卖批评引发的思考

中国首次对野生动物狩猎权进行拍卖引起了社会各界的强烈反响。就媒体的批评,提出一些观点,公众对狩猎权拍卖引发的争论确实体现了民众对野生动物保护意识的增强,这无疑会有利于我国今后野生动物保护事业的顺利发展。但从中也应看到,一些民众片面强调绝对保护的观点存在一定误区。事实上,合理、适度地利用野生动物资源,不仅不会破坏野生动物种群的增长,相反会有利于野生动物保护。     

The potential of oral vaccines for disease control in wildlife species

Numerous infectious diseases caused by bacteria or viruses persist in developed and developing countries due to ongoing transmission among wildlife reservoir species. Such diseases become the target of control and management programmes in cases where they represent a threat to public health (for example rabies, sylvatic plague, Lyme disease), or livestock production (for example bovine tuberculosis, brucellosis, pseudorabies), or where they threaten the survival of endangered animal populations. In the majority of cases, lethal control operations are neither economically feasible nor publicly supported as a practical means for disease management. Prophylactic vaccination has emerged over the last 15 years as an alternative control strategy for wildlife diseases, mainly driven by the success of widescale oral rabies vaccination programmes for meso-carnivores in North America and Northern Europe. Different methods have been trialled for the effective delivery of wildlife vaccines in the field, however oral vaccination remains the most widely used approach. Successful implementation of an oral wildlife vaccine is dependent on a combination of three components: an efficacious immunogen, a suitable delivery vehicle, and a species-specific bait. This review outlines the major wildlife disease problems for which oral vaccination is currently under consideration as a disease management tool, and also focuses on the technological challenges that face wildlife vaccine development. The major conclusion is that attenuated or recombinant live microbes represent the most widely-used vaccines that can be delivered by the oral route; this in turn places major emphasis on effective delivery systems (to maintain vaccine viability), and on selective baiting systems, as the keys to wildlife vaccine success. Oral vaccination is a valuable adjunct or alternative strategy to culling for the control of diseases which persist in wildlife reservoirs.     

广东大峡谷自然保护区社区公众野生动物保护意识调查

2008年6月,对广东大峡谷自然保护区社区公众野生动物保护意识进行了问卷调查。结果表明：（1）公众对野生动物保护知识匮乏,缺乏野生动物保护法制意识;（2）公众普遍对野生动物面临的威胁有较明确的认识,具有保护意愿,但缺乏保护野生动物的积极性和主动性;（3）公众接受野生动物保护教育的主要途径是电视。本文针对广东大峡谷自然保护区公众野生动物保护意识现状及其存在的问题,提出了一些建议。     

Canine vaccination--providing broader benefits for disease control

This paper reviews the broader benefits of canine vaccination to human and animal health and welfare with an emphasis on the impacts of mass dog vaccination against rabies in countries of the less-developed world. Domestic dogs are the source of infection for the vast majority (>95%) of cases of human rabies worldwide, and dogs remain the principal reservoir throughout Africa and Asia. Canine vaccination against rabies has been shown to dramatically reduce the number of cases in dogs, the incidence of human animal-bite injuries (and hence the demand for costly post-exposure prophylaxis) and the likely number of human cases, primarily in children. Further benefits include the mitigation of the psychological consequences of rabies in a community, improved attitudes towards animals and animal welfare and reduced livestock losses from canine rabies. Mass vaccination has recently been used in the conservation management of wild carnivore populations threatened by transmission of rabies and canine distemper virus from domestic dog populations. Vaccination of wildlife hosts directly may also provide an option for mitigating infectious disease threats. The development of integrated control measures involving public health, veterinary, wildlife conservation and animal welfare agencies is needed to ensure that control of canine diseases becomes a reality in Africa and Asia. The tools and delivery systems are all available--all that is needed is the political will to free the world from the ongoing tragedy of these diseases.     

Human–wildlife conflict and attitude of local people towards conservation of wildlife in Chebera Churchura National Park,Ethiopia

Human–wildlife conflict is a serious challenge undermining the integrity of protected areas in developing countries. Developing effective human–wildlife conflict mitigation strategies requires an understanding of the conflict patterns, species involved and attitudes of local people living along protected area boundaries. We hypothesised that (1) there was a high level of human–wildlife conflict and (2) the local people would have less favourable attitudes towards problematic wild animals. We assessed patterns of human–wildlife conflict and attitudes of local people along the boundary of Chebera Churchura National Park, Ethiopia from 2012 to 2014. A total of 354 households were selected randomly for interview. A questionnaire survey, focus group discussions and direct field observations were carried out in the selected villages. The major types of human?wildlife conflict in the area include crop raiding, livestock predation, increased risk of livestock diseases and direct threats to human life. A majority of the respondents (68.1%) faced crop damage and domestic animal loss, 12.3% reported threat to humans and 0.3% reported that the wildlife might cause diseases. Close proximity of the villages to the park and seasons influenced livestock predation intensity with highest predation in the wet season (56.0%). To mitigate these problems, the local people utilised various traditional methods, including guarding. Most respondents had positive attitudes towards the conservation of wildlife. However, as the frequency of conflicts increased in the last five years, the attitudes of local people might change. Active measures are to be implemented to mitigate the problem and safeguard the future of the wildlife around the park. The park has enormous potential to benefit more local people by implementing a participatory management approach to conservation.     

Rabies postexposure prophylaxis. Human and domestic animal considerations.

The emphasis on rabies control and prevention in the United States seems to be a function of our perception of proximity of the threat. Wildlife rabies epizootics within a state may be of little concern to the uninformed urban dweller. Additionally, many parts of the western United States are free of terrestrial rabies; were it not for the presence of bat rabies, people in those areas would likely interpret rabies control as a minor public health concern. It is essential that federal, state, and local public health programs emphasize the importance of rabies control through activities that include rabies education, sponsorship of legislated requirements for domestic animal vaccination, support for local animal control programs, and the promotion of recommendations that encourage the appropriate use of PEP. We are almost guaranteed that rabies is going to remain a major public health issue well into the next century because of expanding wildlife rabies epizootics, identification of new rabies viral variants with increased public health concern, emotional and legal concerns associated with rabies exposure, and increasing national cost associated with rabies control and prevention. Nevertheless, the development of new laboratory technology that allows an understanding of the epidemiologic nature of the rabies virus based on an evolving genetic history and the interrelationship with wildlife reservoirs should allow access to valuable tools for rabies control. When combined with programs using new developments in oral rabies vaccine that can immunize whole populations of wildlife reservoirs, that technology offers encouragement in our effort to control one of the diseases of antiquity.